What do system interfaces figures illustrate?

• A. How systems connect and interact, clarifying where faults can propagate.
• B. They show only physical dimensions.
• C. They are used to train pilots only.
• D. They show electrical wiring colors.

Answer: (C)

System interfaces figures show how different aircraft systems connect and interact, and where faults can propagate between subsystems. They map the boundaries between components, detailing what signals, power, hydraulics, pneumatics, or data paths cross each interface and how control and information flow between systems.

This helps engineers and technicians understand dependencies, plan tests, and assess how a failure in one area might affect others. It goes beyond just physical size, training use, or wiring color codes, which are not the primary purpose of these diagrams.